Disable autocall for prefilter test

IPython/core/tests/test_prefilter.py

@@ -28,6 +28,7 b' def test_prefilter_shadowed():'
 
     prev_automagic_state = ip.automagic
     ip.automagic = True
+    ip.autocall = 0
 
     try:
         # These should not be transformed - they are shadowed by other names